In a wireless multi-hop ad hoc network, a user's communications terminal (e.g., including base station, access point) is used as a relay terminal for performing another user's communications. The user of the relay terminal is to absorb the costs regarding the communications of the other user. In a case of wireless communications, the location of a relay terminal of the user is not fixed, unlike that of wire communications. Thus, the cost is absorbed for relay changes whenever the relay is performed. For example, in a case of relaying nodes that are located far from each other, a large amount of electric power is consumed (a large amount of cost is absorbed) whereas a small amount of electric power is consumed in a case where the distance between nodes is short. Therefore, calculation of cost by merely counting the number of relays as with the conventional wire communications would cause unfairness. This unfairness is a problem that occurs due to the characteristics of the multi-hop ad hoc network. This may be the psychological or economic reasoning that prevents popularization and expansion of the ad hoc network. This unfairness of cost has a greater psychological influence on the user particularly in a battery driven wireless network because this unfairness of cost affects the length of the standby time of a terminal.
Patent Document 1 discloses granting benefits by adding points whenever one uses a function or resource of one's terminal as a relay terminal for others, so as to increase the number of users that can perform relay, moreover, increase the number of service areas. However, how the points (i.e. costs) are calculated is unclear. Further, in a case where such costs are associated with benefits, there is a need to prevent unauthorized obtaining of points by security phishing. However, how it is prevented is unclear. An increase in the number of users willing to perform relay and the expansion of service areas can be induced only where the points and costs can be accurately and safely calculated. However, no such technology has yet been reported. Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-123781